Cloud storage is an emerging technology that uses functions such as the cluster application, grid technology, or a distributed file system to gather numerous storage devices of different types in a network through application programs to jointly provide external data storage and remote access services. The cloud storage has a wide application prospect.
In existing technologies, a typical cloud system may include a client, a cloud server that manages numerous storage devices, and a network connecting the client and the cloud server. A user using the typical cloud system may acquire desired data from the cloud server by using the client to perform the following steps:                S1: the client reads, through the network, a target file located in the cloud server; and        S2: the client caches, locally in real time, relevant data of the target file read from the cloud server, for the user to refer to.        
In the existing technology, the client caches the relevant data of the target file for the user to refer to by reading data from the cloud server through the network. If some problems affecting transmission occur during data transmission (e.g., a network delay), the efficiency of data read by the client from the cloud server may decrease and the user may not receive the desired data in time.